Railway signaling system.



0. LE 6. FORTESC UE.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED JUNE 4.1915.

Patented July 2, 1918.

INVENTOR Glwr/ea LeG. Forrescue.

ATTbRNEY WITNESSES: 6 w. 6%

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g ppsn ELECTRIC AND MA UFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA. a

Applicat on filed time '4, 1915. serial 1%. 32,186.

To all whom it concern Be ltkIlbWh-thfitl, CiiAuiin's Ln G. Foj11- 'r1-isoUii,:a ubject of the King of Great Britain, a resident of Pittsburgh; in the county of Allegheny and State of Pennsyl- Vania, have invented a new and ImprovementinRailw'ay signaling Egyst'enns bf which the following is a specification,

My invention relates to tra'cli-cireuit a1 para't'lis for railway signaling, and it has special reference to railway signaling systerns Which are operated by alternating currents, H U

My invention refers particularly to sig: nailing systems Wliiehare employed ih can ne'ction With tracks that are divided into blocks or sections of suitable lengths. The blocks are insfulated froi'n one anothen 'a'nd each'is provided with at least one suitable signaling device which is operated by ineans of analternating-current Inotor.

one obfect of my inventionis to provide a railwayslgnaling system which will indicate by any suitable means, Whether or not the track.

a trainer ca occupies a certain block of Moreover, signaling system will indicate danger to an ap roachingtrain or car when one of the rails comprising a block of th efirailway track is b'rok'en. According to my invention; a 'se' na'phore signal, or anyother suitable device, such as a signaling lamp, which may be employed to communicate the condition ofthe track of a railivay syst'em, vvill operate to indi; cate danger, either when a block is occupied by a train orcan-or when a rail coihprisin'g a block section broken. Iv

Railway signaling systems emb'od' ingm invention may be emp oyed on ste" In rail- Ways or on electrical railways, whether 01)- erated froin direct-current or alternating current circuits. Current supplied to one ofthe circuits comprising Ihy signaling system is furnished from separate mains which, in turn; are continuously supplied With power from a separate source of power sup} ply: If the propulsion e'urrent utilized for the trains or cars of the railway syste'r'u is furnished -flOlI1 alternating-current mains, itsis desirable that the frequency of the propulsion current be difi'erent from y the frequeircy of the aforementioned current supplyinglpower to the signaling system.

i In stems new installed, it is usual ta operate-Le trains m eale tli'e railway iii un m i Specification of Letters Patent.

littered y a ,1 systern from 25eycle ma ns, and to operate the s gnal ng device's employed in connection wlthth'e railway system 'ey'cle mains. Under these circumstances, hiy-signaling systemmay be so uesighed that it Will operate When (SO-cycle cu'rifent ohly is supplied thereto, and,1asa result, it Will'be unafi'ected when ass-cycle eurrenttrayerss the ailway system; ,i

For a better understanding of thehature of my invention, reference may be' had to the following description and the accompanying drawihgin which Figure 1 is a diagram- Inatic View of a railwa' fsyst'eni embodying a form 'of my inventi n, and Fig. 2 is a iew, in elevation; of a moaifiearotm ora signaling device built in aco'rdanee with my invention. i 7

Referring to Fig, 1, track rails" 1 and 2, Whih comprise an insulated section or bl'oc of a railwaysysteni, are electrically insulated from adjoiniiig mils 4 by ineaiis of iiisiilatihg" Joints 5. The railway heie shown is an [electrical railway, the propulsion current for .ju'hich'is supplied from any suitable source in anywell known manner. 7

In order that ,both time track mile 1 and zmaybe included in the circuit ofthe ropulsion Ql1l'1fl1t,,1 provide inductive b i ds 6, adjacently disposed aiid OlhflCll side-bfthe insulatingj'oiiits 5, a) Canaan the r0 pulsioii current around these joints in a usual an ell known manner; t

A signaling deV1C 7, which th s 1nstance, is provided with a re atable' semaphoi'e arm 8, is positioned at one end 'of' condition to anew an'approachinig traiii 6rcar. to enter into said blocln y 1 The operating meham'sm'to yaiy the position of the sem'a' hone 8 a horizontally movable actuat ng arm 9*that.

is operated by a centrifugal deYice 'llsby means of a rotatable secondaryineiiiber -B of an induction intitor 13. Agpriinary'wiiid in 14 oftli'e induction inotor i3 i h i 9. l lyli l, w ne-1 5%, 3L threepliase mains endsfiiiphed w: H "power Op r d 7 phase alternator 16.

block. 3. The centrifugal device. 11, which comprises'lpivotally mounted links 21 and elements22 that are. .well known in the art a ternal resistance -.connected in circuit with from any suitable source, such as a three- As 'men'tioned above, the induction motor 13 comprises a stator having the primary ,winding l-it and the rotor 12 which is provided 'With' two Windings 17 and*18so disposed'thereupon. as to grees .from eachother. The windings 17 and 18 are connected in parallel relation-- ship and, throu'gh slip'rings 19. and 20, to the track rails. land 2, respectively, of the and in:;.common use in governing devices, is

mounted upon-the shaft-23- of the induction motor; 13. Que endof .the governing device 11 is secured to the? shaft 23; by -means of a pin 2 1, and-the other end: engages. a collar whichis slidingly' mounted on' the shaft The position of the 001152125 is dependent upon the speed of the shaft23 by reason ofthe interposed centrifugal mechanism comprising the elements 21.

actuating arm. 9 of the; semaphore arm 8 is memberlO which' is' rotatedfby means of engagement through an arm. 2GW1tl1j the aforementionedcollar 2.5

Under. normal condit'ons, when no train or. car occupies the block-3, thesecondary member 12 of'the-induotion motor 13; ro-' rates at a speed considerably be1ow synchro nism, such, for instance, as one-halffsyn chronousspeed. This-results from the designjof. themotor 13 and from the BX.

. the secondary windings17 and 18 by reason ofthe trackcircuit formed by the rails 1 and .2f'and. thefimpedancebonds .6. Inasmuch asthe rails 1 and 2 and the impedance bonds 6 constitute a high resistance which, in turn,:is connected in circuit with. the secondarywindingsiof theinduction. motor 13,

the speed 5 of the secondary. member is" main+ tained considerably. "below! synchronism.

' a ca .311 oecup ie ltheihl ekT3,

nder. these circumstances, the centrifugal QV Q; P t Posit o own y the dottedlines 27, andthe cam.member 1( c upies a up *pe n. ind a e y. the-dotted lines 28. Sincethe actuating arm 9. iof the signal-armfi tends tomove toward; the cam member '10 byreason of the gravity;-= action. of the arm 8, the actuating arm-91 0ccupies a position; indicated byfthe' dottedv lines 29, and the} semaphore arm .8 occupies the. position indicated by the dotted ,lines In this manner, the .lconditions obtainmgJ1-PQ Z h1eb1Qd anemia t at t e blok s;openpmaysbecommunicated to an .ap-g Pr chingt n-pe a ltlieirailsl i and- 2; are directly; connected tq the ai i'euehz e et: an a a e h -tact th een?essence' in be displaced do and 22. The:

1 occupies the position 3 3,;thev semaphore arfm by..means of the rotatable cam 8 occupies thepositionshown in. theffull V cam'member 10 occupy the positionsjshown by the full lines. Inasmuch as the cam 10 Lis turned to such position as to force the ac tuating arm 9 away from the centrifugal device '11, the semaphore arm 8 occupies .a

horizontal position; thereby indicatingithat' theblock'3 isoccupied. After.th e train 31 withdraws from the blockB -normal'con 5 ditions arerestored uponthe railway sys-f r tem, and the rotor--12; of the induction mo;- tor '13 will rotate at its normal speed. When;

arailof the sectionv 3 breaks thesecondary windings {17 and 1810f the. rotor 12 are open-' circuited. As is. well known, the rotorT12 will cease to rotate and-the centrifugal de- 10 will occupy a positlon indicated bythej dotted lines 33, When the'cam device 10 lines, to indicate. danger.

Since the motor 13-isdes1gned operate at substantially ,.one-half synchro nous speed, for.example,i50.per centkof syn-ff chronous speed, it willnot-be' influenced tol plied ,with 60-cyclecurrents. Inasmuch as; substantially" one-half synchronous speed of; a themotor correspondsffor all. practical pun poses, to the rate of ;jviloration.impartedv thereto by 25.-cycle currents, it-will be apparentthat 25-cycle currents will not-affect the reliability of my signaling system, asis common-Yin manyi'systems; heretofore installedi. 1 c

In'the foregoingdescription -l have (is,

closed a railway signaling system which. will. 1110 operate: ,to indicate danger "when: either a tr'ain'or a car occupies the. blocki 3,: or 'when either one. orboth of, the rails l and-2 comprlsing the block 3j-is broken. It may be;

unnecessary, however, to. provide means; to 1:15

indic-ateabroken rail becauseof the .infrea I .quency; of suchfan occurrence. "I-herefo're,v V I mayjemployathe arrangement.showm'inii Fig. 2', in which the secondary w'indings17'a V and 18 of Fig. 1 ofthe induction-motor13.120.

are sodesigned that theywill not .-eifectrota-J tion of the shaft 23 when: connected'in- 'cir 1 .cuit withthe'ra ils 1 and 2*andtheim-pedance; bonds 6. r In this case, the. impedancegofthey. rails and .bondslis toohigh-"to permitfthe glzfi rotor windings to developfsufiicient torqueiila. 2 Ito-rotate the Shaft 23. ".In' other words, the Q secondary membe1- ;offl1e induction motoryrs J 1. remains-j stationary whe normal conditions i obtain upon the block 1. 31s a l'consequence savice 11 will then occupy aposition indicated by thedotted lines 52, a'nd the cam .gl vfi i shown in Fig. 1, the resistance nalin bination with thereof, the centrifugal devicell: occu ies t r t on Shawn by. t ful n s-9i t 2. The slidingly mounted ,collar operates a linkfmechanisin 34gto i-main'tain tilnsemin- PhQre arm, 8, in the .positi n indiicated.

Je a rain e a upies of the secfondary circuit of the induction motor 13 is sufficiently: decreased, to compelthe {shaft 23 to rotate at substantially Synchronous speed. Under-1' these a conditions, mechanism 11 occupies a position indicated by the dotted lines 35. Smce the collar 25 is drawn toward the motor 13 when the shaft 23 rotates, the link mechanism 34 is operated to move the semaphore arm 8 to a position indicated by the dotted lines 36. As previously explained, when the semaphore arm 8 is in the position 36, the approaching train or car is warned against advancing into the block 3.

It is to be understood that other signaling devices, such as those embodying lamp signals, may be substituted for the semaphore type of signal; that other actuating devices may be substituted for the centrifugal device 11, without departing from the spirit of my invention, and that other modifications may be made by those skilled in the art within the scope of the appended claims.

claim as my invention:

1. In a railway si naling system, the combination with a traci circuit and a signaling device, of an operating means for said signaling device comprising relatively rotatable primary and secondary members one of which has a windin connected to the track circuit and provider withresistance in its circuit that is controlled by track circuit conditions.

2. In a railway signaling system, the combination with a track circuit and a signaling device, of an operating means for said signaling device comprising an induction motor the primary member of which is supplied with polyphase alternating current energy, and the secondary member of which has a winding connected to said track circuit.

3. In a railway signaling system, the combination with a track circuit and a signaling device, of an operating means for said sigdevice comprising an induction motor t e primary member of which is supplied with alternating current energy, and the, rotatable secondary member of which has windings displaced in phase relationship with one another and connected to said track circuit.

4. In a railway signaling system, the coma track circuit and a signaling device, of an operating means for said signaling device comprising an induction motor the primary member of which is supes plied with alternating current energy to the, a centrifugal;

generate a rotatingrficld and, the rotatable ie evdal'y, mber of area. a w ndings connectedinparalleh o therails constituting le se t o v i-t 1e? ai y syat enthe lr li ir sietai ee effi aid second ry windi s ei g s le l lsil d-ith r wh n a r i e br d es-the rails 10f "s d lo k-se tio the saidsniember rotatesat its highest speed-.j ,5-,.:. n,a.-1'i i a signa g sys ms t eme: binationwith a track circuit and a signaling device, of an, operating means for saido'sigi inal' device comprising an induction motor t e primary member of which is supplied with alternating currents to generate a rotating magnetic field and the rotatable secondary member of which has windings connected in parallel to the rails comprising a block section of the railway system in order that the circuit resistance of said secondary windings may have a minimum value when a train or car bridges the rails. of said block section.

6. In a railway signaling system, the combination with a track circuit and a signaling device, of an operating means for said signaling device comprising an induction motor the primarymember of which is supplied with alternating currents to generate a rotating field and the rotatable secondary member of which has windings connected in parallel to the rails comprising a block section of the railway system, the circuit resistance of said secondary windings being so adjusted that the secondary member will rotate normally at a speed substantially below synchronism and, when a train or car bridges the rails of said 'block section, the secondary member will rotate at substantially synchronous speed.

7. In a railway signaling system, the combination with track rails, bonds for connecting them to each other, and a signaling device, of an operating means for said signaling device comprising an induction motor the primary member of which is supplied with alternating currents to generate a rotating field and the rotatable secondary member of which has windings connected in parallel relationship to the track rails comprising a block section of the railway system in order that said block section may normally be connected in a closed circuit with said secondary windings.

In a railway signaling system, the combination with a track circuit and a signaling device, of an operating means for said signaling device comprising an induction motor the primary member oil which is sup plied with alternating currents to generate a rotatin field and the secondary member of which as windings connected in a circuit comprising a block section of'the railway system in orderthat the said windings may be open circuited when one of said rails is broken. 

